LAUSR

Background Systemic juvenile idiopathic arthritis (SJIA) is a distinct form of juvenile idiopathic arthritis (JIA), accounting for approximately 4% to 17% of JIA1. In Japan, a higher frequency of SJIA, 41.7% of JIA2 has been reported compared to Europe and United States. Tocilizumab (TCZ) is the only approved biologic for SJIA treatment in Japan. However, some patients (pts) demonstrate persistently high disease activity and/or drug intolerabiliy. Therefore, new treatment options are required. Here, we evaluated the efficacy and safety of canakinumab (CAN), a human anti-interleukin-1ß monoclonal antibody, in Japanese SJIA pts. Objectives To report the results of a 28 week (Wk) interim whole analysis of Phase III data (NCT02396212) of CAN, and the subgroup analysis of pts with or without prior use of TCZ. Methods Patients (age ≥2-<20 years) received open-labelled CAN 4 mg/kg (max 300 mg) every 4Wks (q4w) subqutaneously (s.c.). The primary objective was to evaluate the proportion of pts who achieved 30% improvement from baseline of adapted ACR Paediatric criteria (aACR 30) at Wk8 and who achieved corticosteroid tapering at Wk28. Steroid reduction was allowed from Wk8. We also analysed the data with or without prior use of TCZ. Results The trial enrolled 19 pts who had insufficient response to prior treatment; the majority (15/19, 78.9%) had received TCZ (table 1). Of the 19 pts, 3 discontinued CAN due to lack of efficacy or adverse events (AE) by Wk28 and 16 completed the assessment of Wk28. All pts (19/19) achieved aACR 30/50/70 at Wk8 (figure 1). Overall, 73.7% (14/19) pts achieved corticosteroid tapering at Wk28 and 2 pts (10.5%) achieved ”steroid free”. Of 15 pts with prior use of TCZ, 12 pts (80.0%) achieved aACR 100 at Wk8 and 11 pts (73.7%) achieved corticosteroid tapering (26.3%, 5/19). Serious AE (SAE) was seen in 41.1% (8/19) pts, and the most frequent SAE was JIA (flare or worsening of SJIA, 21.1%, 4/19). One macrophage activation syndrome (MAS) but no death was reported.Abstract THU0599 – Table 1 Patient Characteristics Characteristic G1301 trialn=19 Male (%) 6 (31.6) Age (mean) 9.9 BMI (kg/m2) (mean) 19.59 Time from SJIA diagnosis to study entry (years) (mean) 6.1 CRP at baseline (standardised in mg/L) (mean) 357.79 Oral prednisone equivalent dose (mg/kg/day) (mean) 0.309 Oral steroid use at baseline - n(%) 19 (100) Number of active joints (mean) 6.3 Number of joints with limitation of motion (mean) 4.4 Prior use of tocilizumab (%) 15 (78.9)Abstract THU0599 – Figure 1 Efficacy of canakinumab with adapted ACR Paediatric criteria in sJIA patients with/without prior use of tocilizumab (TCZ) Conclusions CAN 4 mg/kg q4w s.c. provided improvement in disease activity and a redution of oral steroid dose in Japanese SJIA pts, including those who were not well-controlled with TCZ. No new safety concerns were reported. References [1] Ravelli A, Martini. Lancet2007; 369(9563):767–78. [2] Takei S, et al. Annual Report on children with chronic refractory diseases from the Japanese Ministry of Health, Labor and Welfare2008;102–13. Disclosure of Interest None declared